There has always been a problem when firing medium to large caliber projectiles from a small enclosure from any type of launching device, having low location signature of flash and/or smoke, with minimum impact of overpressure and noise on both the launch crew and their environment. Conventional closed-breech weapons cause severe overpressure and emit toxic fumes when the projectile propellant gases expand from the muzzle as well as producing a recoil problem. Prior art recoilless weapons eliminate the recoil problem but release additional propellant gases from the rear of the weapon thereby increasing the overpressure, toxic fumes, and signature problems. Conventional prior art rockets also produce severe signature and overpressure problems when launched from an open tube type launcher. The overpressure developed when firing out of an open window in a normal urban sized room indicate pressures are sufficiently high to cause internal injury to the gunner. Also, repeated firings within a short period of time produce enough toxic fumes to make the enclosure uninhabitable.